Safety device for refrigeration systems



Jan. '12, 1937.

N. a. FINNEY v SAFETY DEVICE FOR REFRIGERATION SYSTEMS Filed Jan. 15, 1934 Patented Jan. 12, 1937 UNITED STATES PATENT OFFICE SAFETY DEVICE FOR REFRIGERATION SYSTE In refrigerating systems where a refrigerant such as sulphur dioxide is cooled in a heat exchanger through which cooling water flows, damage frequently results from small leaks which permit communication between the refrigerant circuit and the cooling water system. When any such leak occurs the sulphur dioxide, being under. relatively high pressure, escapes into the water system; but eventually, as the pressure in the refrigerant-circuit drops, some water finds its way into the refrigerant circuit, forms sulphurous acid with the sulphur dioxide, and may seriously corrode and otherwise damage the refrigeration apparatus.

It is the object of my invention to prevent the.

occurrence of damage as the result of any accident whereby the refrigerant comes into associ-- readily attached to any existing refrigerating system and which will become operative upon acidification'of the water at least to give notice of the dangerous condition and preferably to stop the operation of the refrigeration apparatus.

In carrying out my invention I provide a pair of electrodes insulated from each other and exposed within a chamber separated from the cooling water by a diaphragm which is subject to corrosion by the acid or other compound formed when the refrigerant combines with the cooling water. Should a leak occur whereby the refrigerant would enter the circulating water system, the resultant acid formed would dissolve such diaphragm and enter the electrode-containing chamber completing a circuit between the electrodes. Completion of that circuit can be availed of for performing any desired operation, such as ation of the refrigerating apparatus.

The accompanying drawing illustrates my in- I vention: Fig. 1 is a diagrammatic view showing apparatus embodying my invention associated with a refrigerating system, and Fig. 2 is a section on an enlarged scale through a portion of the apparatus shown in Fig. 1.

My invention is not concerned with any details of the refrigeration apparatus, which is indicated only diagrammatically in the drawing. Refrigeration apparatus of the compression type, which is indicated in the drawing but to which my invention is not limited, embodies a compressor i0 which compresses the refrigerant and delivers it to a cooler II from which the refrigerant passesthrough the remaining portion of the apparatus indicated diagrammatically by the dotted lines i2 and back to the cornpressor. It is customary to cool the refrigerant in the cooler II by means of a cooling coil I! having its endsfconnected respectively to a'water supply. pipe ll and a discharge pipe l5. Some suitable source of power, such as an electric motor i6 is employed to drive the compressor ill. A device embodying my invention is conveniently associated with apparatus such as has just been described at the polntwhere the cooling coil II is connected to the discharge pipe i5.

If such a location is desired, the connection to thecooling coil 13 of the discharge pipe l5 may be by means of an ordinary pipe vT ll. In that opening of the T which is not connected to either of the pipes 13 and I5, I may mount the device embodying my invention.

As shown in the drawing, that opening of the T i! which is not connected to the pipes l3 and i5 receives a plug i8 having an inwardly opening central chamber l8 closed by a relatively thin diaphragm 20 of some material which will be subject to the action of sulphurous acid. Within the chamber i9 I provide an electrode 2| which is suitably insulated from the body of the plug l8. The latter may be of metal and which may con-.

and the body of the plug it may be availed of to In the arrangement secure the desired result. illustrated in the drawing, the electrode 2! is connected by a wire 24 to one of a pair of currentsupply wires 25 and 26, and the body of the plug I8 is connected through a wire 21 and the winding'of a relay.28 to the other of such currentsupply wires. The relay 28 has a movable contact 29 and two fixed contacts 30 and 3|, the former of which is engaged by the movable contact 29 when the relay is deenerg zed and the latter of which is engaged by the movable contact when the relay is energized.

The motor l6, which operates the compressor l0, may be connected to the current-supply wires 25 and 26 through the contacts 29 and 30, so that upon energization of the relay the supply of current to the motor [6 will be cut off. If desired, warning signals such as a bell 32 and a lamp 33 may be connected to the supply wires 25 and 26 through thecontacts 29 and 3! so that both visible and audible indications will be given when the relay 28 is energized.

-In the operation of apparatus in which my invention is embodied, the diaphragm 20 remains intact as long as the water flowing through the pipes i4 and I6 and coil I3 is not acidified. However, should a leak occur in the cooling coil l3, the sulphur dioxide in the cooler ll would enter the water system through the leak and would react with the water to form sulphurous acid.

This acid would then act upon the diaphragm,

disintegrate it, and enter the chamber I9 where,

being an electrolyte, it would complete a circuit a between the electrode 2| and the body of the i0 plug I! to energize the'relay 28, shut off the supply of current to the motor l6, actuate the warning bell 32, and light the warning lamp 33.

As the principal parts of my invention can be embodied in the plug IE, it is a simple matter to 16 incorporate the invention in any refrigeration apparatus. For use with systems in which sulphur dioxide is the refrigerant, the diaphragm 20 may be of zinc and 0.020 inch in thickness or even thinner.

I claim as my invention:

1. In combination, a fluid-conveying conduit, a heat-exchanger through which said conduit passes, said heat-exchanger containing a second and different fluid in contact with the exterior of said conduit, said conduit being provided with an opening in one wall, a closure member for said opening, said member being formed of material subject to corrosion by a mixture of said two fluids, a warning signal, and means actuated by the passage of a mixture of said two fluids through said opening for operating said warning signal.

2. In combination, a fluid-conveying conduit, a heat-exchanger through which said conduit passes, said heat-exchanger containing a second and different fluid in contact with the exterior of said conduit, said conduit being provided with an opening in one wall, a closure member for said opening, said member being formed of material subject to corrosion by a mixture of said two fluids, and mechanism actuated by the passage of a mixture of said two fluids through said opening for stopping operation of said fluid-circulating means.

3. In refrigeration apparatus having a heatexchanger through which separately pass a refrigerant and a liquid which, when mixed, form an electrolyte, supply and discharge conduits for conveying the liquid to and from said heat so exchanger, means forming a chamber adapted to communicate with said discharge conduit, conducting means associated with said chamberforming means and including an insulated electrode exposed within said chamber, a closure for 55 normally preventing entrance of the liquid into said chamber from said discharge conduit, said closure being formed of material subject to corrosion by the action of a mixture of the refrigerant and the liquid, a source of electric current and an electrically operated warning signal connected together through said conducting means.

4. In refrigeration apparatus having a heatexchanger through which separately pass a refrigerant and a liquid which, when mixed, form an electrolyte, supply and discharge conduits for conveying the liquid to and from said heat-exchanger, means forming a chamber adapted to communicate with said discharge conduit, conducting means associated with said chamberforming means and including an insulated electrode exposed within said chamber, a closure for normally preventing entrance of the liquid into said chamber from said discharge conduit, said closure being formed of material subject to corrosion by the action of a mixture of the refrigerant and the liquid, a normally closed electromagnetic switch openable when energized to stop operation of the refrigeration apparatus, and a source of electric current connected to the coil of said electro-magnetic switch through said conducting means.

5. In refrigeration apparatus having a heatexchanger through which the refrigerant and the liquid separately pass, supply and discharge conduits for conveying the liquid to and from said heat-exchanger, means forming a chamber adapted to communicate with said discharge conduit, a closure for preventing communication between said chamber and said discharge conduit, said closure being formed of material subject to corrosion by the action of a mixture of said refrigerant and liquid, a warning signal, and means responsive to the presence in said chamber of a mixture of said refrigerant and liquid for actuating said warning signal.

6. In refrigeration apparatus having a heatexchanger through which the refrigerant and the liquid separately pass, supply and discharge conduits for conveying the liquid to and from said heat-exchanger, means forming a chamber adapted to communicate with said discharge conduit, a closure for preventing communication between said chamber and said discharge conduit, said closure being formed of material subject to corrosion by the action of a mixture of said refrigerant and liquid, and means responsive to the presence in said chamber of a mixture of said refrigerant and liquid for stopping operation of the refrigeration apparatus.

7. In refrigeration apparatus having a heatexchanger through which separately pass a refrigerant and a liquid which, when mixed, form an electrolyte, supply and discharge conduits for conveying the liquid to and from said heat-ex changer, means forming a chamber adapted to communicate with one of said conduits, conducting means associated with said chamber-forming means and including an insulated electrode, a closure for normally preventing.communication between said chamber and the conduit with which it is associated, said closure being formed of a material subject to corrosion by the action of a mixture of the refrigerant and the liquid. 9. source of electric current, and an electro-responsive device connected to said current source through said conducting means.

NEWELL B. FINNEY. 

